The nitrogen dynamics in a subsurface infiltration system (SIS) are affected by many factors, including temperature, system design, and feed water quality, which are not easily quantified. In this study, a column experiment was conducted to simulate an SIS. The HYDRUS-1D software package was used to investigate and quantify the factors that affect nitrate transport in an SIS. Three treatments were carried out based on different hydraulic conditions, including continuous wetting (CW), wetting/drying (WD), and a specific hydraulic loading rate (SH). The effects of hydraulic conditions and temperature on nitrate transformation were investigated. The model was calibrated and validated using two-year experimental data. Simulations of cumulative outflow volume and nitrate concentration fitted well with the observations. Among the three SISs, the denitrification rate was greatest under unsaturated conditions at high water temperature. The denitrification rate constant had an exponential relationship with temperature. An empirical formula describing this relationship was developed and validated in the SIS. The results showed that the SH column attained the greatest nitrate removal efficiency, mainly due to its low hydraulic loading and long retention time. Overall, the results showed that HYDRUS-1D adequately simulated nitrate transport through the soil column under different temperature and hydraulic conditions in an SIS. The fate of nitrate was directly controlled by the water temperature and hydraulic conditions.

地下渗透系统（SIS）中的氮动力学受许多因素影响，包括温度，系统设计和给水质量，这些因素难以量化。在这项研究中，进行了柱实验来模拟SIS。HYDRUS-1D软件包用于调查和量化影响SIS中硝酸盐迁移的因素。根据不同的水力条件进行了三种处理，包括连续润湿（CW），润湿/干燥（WD）和特定的水力加载率（SH）。研究了水力条件和温度对硝酸盐转化的影响。使用两年的实验数据对模型进行校准和验证。累积流出量和硝酸盐浓度的模拟与观察结果非常吻合。在三个SIS中，在高水温下不饱和条件下反硝化率最大。反硝化速率常数与温度呈指数关系。在SIS中开发并验证了描述这种关系的经验公式。结果表明，SH柱获得最高的硝酸盐去除效率，这主要是由于其水力负荷低和保留时间长。总体而言，结果表明，在SIS中，在不同温度和水力条件下，HYDRUS-1D可以充分模拟硝酸盐通过土壤柱的迁移。硝酸盐的命运直接受水温和水力条件控制。在SIS中开发并验证了描述这种关系的经验公式。结果表明，SH柱获得最高的硝酸盐去除效率，这主要是由于其水力负荷低和保留时间长。总体而言，结果表明，HYDRUS-1D在SIS中在不同温度和水力条件下充分模拟了硝酸盐通过土壤柱的迁移。硝酸盐的命运直接受水温和水力条件控制。在SIS中开发并验证了描述这种关系的经验公式。结果表明，SH柱获得最高的硝酸盐去除效率，这主要是由于其水力负荷低和保留时间长。总体而言，结果表明，HYDRUS-1D在SIS中在不同温度和水力条件下充分模拟了硝酸盐通过土壤柱的迁移。硝酸盐的命运直接受水温和水力条件控制。结果表明，在SIS中，HYDRUS-1D在不同温度和水力条件下充分模拟了硝酸盐通过土壤柱的迁移。硝酸盐的命运直接受水温和水力条件控制。结果表明，在SIS中，HYDRUS-1D在不同温度和水力条件下充分模拟了硝酸盐通过土壤柱的迁移。硝酸盐的命运直接受水温和水力条件控制。